My first degree came years before my second. I had wanted to be a physicist, but I flunked calculus.
— Elizabeth Moon

Hard to be a physics major at Rice University if you have flunked calculus.
Elizabeth Moon calculus quote

I was more interested in skating and the girls and traveling than I was in calculus.
— Scott Hamilton

Gout produces calculus in the kidney... the patient has frequently to entertain the painful speculation as to whether gout or stone be the worst disease. Sometimes the stone, on passing, kills the patient, without waiting for the gout.
— Thomas Sydenham

Newton, of course, was the inventor of differential calculus so his place in the tale is quite special.
— calculus quotation by Kit Williams